craig, You need a better pic or explanation? If so lemme know

dkeers, keep us posted on how it turns out.

 

Good and Bad:
I tried it out and it did not work as expected. The fuel and N2O noids both opened like they should have but then it started pulsing on and off. I don't think that the problem lies with the theroy of how it is set up though.

I think the problem is that the fpss cannot handle enough amps to provide a good ground for the N2O solenoid. All of the instructions on how to hook up a fpss say that it needs to ground a relay not a direct ground because it cannot handle it.

I think I have a solution to this. I am going to get a second relay and run power to my N2O and fuel solenoids from via separate relays. The same power source will turn both relays on but the N2O relay will only be grounded when the fpss is closed (ie the fuel noid has already opened and my fuel pressure is good)

I thought of another reason that this is a good idea. I have heard other people complain about pulsing from a fpss in a normal setup and I think there is 2 causes: 1) improper grounding (like I had and am fixing) and 2) when the fuel noid opens there is a pressure drop for a split second (think of holding your thumb over a garden hose then letting go - the water shoots out far then drops way back then flows at a constant rate). If pressure drops enough then the fuel noid snaps closed. As soon as it snaps closed the pressure will be back up and it will open again causing another pressure drop. This cycle is repeated and is more noticable on a large shot (150 or bigger). The way I have it set up the fuel noid is not controlled by the fpss so there will be no pulsing caused by the initial fuel pressure drop.

Sorry I have got long winded but I enjoy making anything better than it was designed so this is like a challenge for me now

BTW the delay was not noticable, the N2O hit almost imediately when I pressed the button, but then it pulsed off.

Let me know your thoughts, I would love for this too work. It could save me or someone else a motor. If I get it to work I will start another thread.

Dustin

Edit: When I bypassed the fpss it worked perfect just like before so I know the switch was the problem.

 

I found the one on your page. I just didn't look at the right picture the first time.

 

Dustin,

Try setting the FPSS all the way to its lowest setting, that would eliminate pressure problems it would open then regardless of pressure problems. Mine does that if the fuel pressure is low (car off with fuel in the rail). It doesn't sound like an amperage problem but keep up the work!

Hey I just thought of this also, the pressure is lower on the other side of the solenoid, I bet you anything if you drop the pressure threshold on that FPSS that it will work.

 

That sounds like a good idea, I will try that.

Does anyone know what fuel pressure an Ls1 runs at? I think it is 58 psi but I am not sure.

I don't really know what psi the switch is set at, I need to get a fitting for my air compressor so I can test it.

It might take me a few days to know if it works, it is raining and is supposed to snow saturday.

Dustin

 

Wouldn't setting the pressure all the way down to the lowest setting kind of defeat the purpose of having the FPSS in the first place?

 

Yes it would I meant just for testing to eliminate the possibility of it being an amperage problem.

 

how did this turn out?

 

I haven't changed anything yet. I've been busy and it is hard to get motivated to fix my N2O when it is working how I have it (bypassed fpss).

I saw someone on LS1tech was trying something similar and having trouble as well. I will post if I get it working.

 

Id love to hear how all this turns out. im instaling my nx kit right now and was wanting to put the fpss after the fuel noid (fuel rail,fuel noid,fpss, nozzle) i guess just for extra insurance incase the fuel noid stuck. But now i see the point of how will the fpss have pressure all the time. oh well i guess i'll just mount it before the fuel noid.
What noid do i see on a few of setups attached directly to the bottle?
Does anyone have a real closeup pic of the wot switch? i bought a NOS brand but dont see a real great way to run it without a lot of bending and turning. thanks

 

I'm pretty sure your talking about the one for the automatic bottle warmer.

 

bottle warmer? theres a solenoid for the warmer? i dont think thats what im talking about.

 

It's not a solenoid like you are thinking, but it looks like one, and it for the automatic bottle warmer. The one that uses a pressure sensor to turn the heater on and off.

 

oh ok. i just bought this kit used and it came with the bottle warmer but it was just hard wired to a switch so i guess he wasnt using the thing your speaking of.

where would be a good place to buy one or can i?